# Weber (unit)

The **weber** (symbol Wb) is the SI unit of magnetic flux. It is named for the German physicist Wilhelm Eduard Weber.

The ninth *Conférence Générale des Poids et Mesures* (General Conference on Weights and Measures) ratified in 1948 a definition of weber based on Faraday's law for magnetic induction. Faraday's law connects electromotive force (in volt) to the rate of change of magnetic flux (in Wb/s) through one loop of conducting wire (a "turn"):

If the magnetic flux Φ is linear in time—Φ changes with uniform rate—and if Φ = 0 at *t* = 0, then it follows that

This equation forms the basis of the formal definition, which reads:

One weber is the magnetic flux which, linking a circuit of one turn, would produce in it an electromotive force of 1 volt if it were reduced to zero at a uniform rate in 1 second.(Resolution 2, International Committee for Weights and Measures. 1946).^{[1]}

Dimension: Wb = V⋅s = N⋅m⋅A^{−1} = kg⋅A^{−1}⋅s^{−2}⋅m^{2} = T⋅m^{2},
where A stands for ampere, T for tesla, V for volt, and N for newton.

## Reference

- ↑ BIPM brochure about SI. PDF page 52; paper page 144.